Re: [Vala] using a non-glib C library in vala

[Frederik <scumm_fredo gmx net>]

Jan Hudec wrote:
> What you describe is the meaning of struct. Structs are always allocated
> statically and always passed by value (unless ref modifier is used, of
> course).
>
> Passing by reference is indicated by declaring as 'class'. Classes are
> supposed to support reference-counting, but if they don't, they can be
> declared with [Compact] modifier.

However, passing structs as const reference to functions is common
practice in C in order to avoid unnecessary copying. Vala does that by
default, too. Take this code, for example:

----------------------------------------------------
[SimpleType]
struct Point {
        public int x;
        public int y;
}

void print_point (Point p) {
        stdout.printf ("(%d, %d)\n", p.x, p.y);
}

void main () {
        Point p = { 3, 4 };
        print_point (p);
}
----------------------------------------------------

C code without [SimpleType]:

  void print_point (const Point* p);
  ...
    Point p = {3, 4};
    print_point (&p);

C code with [SimpleType]:

  void print_point (Point p);
  ...
    Point p = {3, 4};
    print_point (p);



Best regards,

Frederik